Every August, a group of 200 intrepid Welshmen don snorkels and flippers, plunge into a thick local peat bog and swim two consecutive 60-yard lengths of trench cut through it. The winner is declared the World Bog Snorkelling Champion. Last year, NBC Olympics commentator Mary Carillo traveled to Wales, put on a wet suit and dove into the muck herself. No, bog snorkelling is not an Olympic sport, but this is one of 17 feature stories Carillo has shot over the past year that will air on NBC next month during the London Summer Games.

“We didn’t want to show just athlete profi les and sports profi les,” Carillo explains. “[NBC] also wanted to show the whole face of Great Britain.”

It’s the typical go-for-the-lines approach of Carillo, the former tennis pro-turnedconsummate broadcast storyteller, whose fearless event commentary, lively Olympics coverage and stories for HBO’s Real Sports With Bryant Gumbel have won the acclaim of fans and producers alike, along with both a Peabody and a Sports Emmy Award for writing and reporting.

Like many former athletes who have become sports broadcasters, Carillo launched her reporting career from the courts of the pro tennis tour. But the similarities mostly end there. While a top player, Carillo was never a superstar. She actually spent a lot of her time hanging out in the press rooms, making her brief tennis career an internship on the way to the booth.

“I love writing and writers, and would watch…how they would craft their stories,” Carillo says. “So even as a player, that’s where I was at the end of the day.”

And it’s where she has largely remained since retiring from the tour in 1980. Carillo has a knack for insight and humor (calling the men’s double luge “like a bar bet gone bad” during the 2002 Salt Lake City Games earned her “Best Line of the Year” from Sports Illustrated) and an openness that draws out her subjects.

That was evident on the May 22 episode of Real Sports. Carillo’s profile of U.S. Olympics hurdler Lolo Jones blew up the Twitterverse after the two discussed Jones’ quest to remain a virgin until she marries. The interview exemplifies Carillo’s “remarkable ability to connect, to empathize with people and give them a comfort zone; that’s what Mary does best,” says Kirby Bradley, senior producer at Real Sports.

“I’m always intrigued by the athletic heart—it’s a muscle unlike most,” Carillo says. “But I would like to find out how other hearts beat, and I think there’s some real room for that.”

That unique ability keeps her busy. Along with Tennis Channel, CBS and HBO, NBC is one of four networks with which Carillo is on contract. The network tapped her as its late-night anchor for the London Games—this will be her 11th consecutive stint at the Olympics— and she will also cover women’s tennis and contribute the pre-taped features.

Those segments will be a “distinctive” addition to NBC’s Olympics coverage and, in part, garnered Carillo her first story for NBC’s Rock Center With Brian Williams, says executive producer Rome Hartman, who worked with Carillo on the piece, a profile of South African paraathlete Oscar Pistorius that aired on June 7.

“Mary stands out for doing stories with a human touch, a certain flair and wit, and that’s unusual among sports broadcasters,” Hartman says. “She’s a terrific storyteller.”

Storytelling is in Carillo’s blood. Her father, Tony, worked on Madison Avenue and his passion for narrative rubbed off on his children; Carillo’s brother, Charlie, is a news producer turned novelist.

And it is long-form narrative that Carillo enjoys most. She has worked on six documentaries, including the Peabody-winning Dare to Compete: The Struggle of Women in Sports. “I hope that’s where my future will lie,” she says.

Wherever it takes her, Carillo’s broadcasting career, unlike her time in tennis, is destined to be of the five-set match variety. “I’m low maintenance,” she says. “Because of my temperament, I end up doing things most people don’t want to. Bog snorkelling is not for everyone.”